// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_ANDROID_EDGE_EFFECT_H_
#define UI_ANDROID_EDGE_EFFECT_H_

#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "ui/android/edge_effect_base.h"
#include "ui/android/ui_android_export.h"

namespace cc {
class Layer;
}

namespace ui {
class ResourceManager;
}

namespace ui {

// |EdgeEffect| mirrors its Android counterpart, EdgeEffect.java.
// Conscious tradeoffs were made to align this as closely as possible with the
// the original Android java version.
// All coordinates and dimensions are in device pixels.
class UI_ANDROID_EXPORT EdgeEffect : public EdgeEffectBase {
public:
    explicit EdgeEffect(ui::ResourceManager* resource_manager,
        float device_scale_factor);
    ~EdgeEffect() override;

    void Pull(base::TimeTicks current_time,
        float delta_distance,
        float displacement) override;
    void Absorb(base::TimeTicks current_time, float velocity) override;
    bool Update(base::TimeTicks current_time) override;
    void Release(base::TimeTicks current_time) override;

    void Finish() override;
    bool IsFinished() const override;
    float GetAlpha() const override;

    void ApplyToLayers(Edge edge,
        const gfx::SizeF& viewport_size,
        float offset) override;
    void SetParent(cc::Layer* parent) override;

    // Thread-safe trigger to load resources.
    static void PreloadResources(ui::ResourceManager* resource_manager);

private:
    class EffectLayer;
    scoped_ptr<EffectLayer> edge_;
    scoped_ptr<EffectLayer> glow_;

    float base_edge_height_;
    float base_glow_height_;

    float edge_alpha_;
    float edge_scale_y_;
    float glow_alpha_;
    float glow_scale_y_;

    float edge_alpha_start_;
    float edge_alpha_finish_;
    float edge_scale_y_start_;
    float edge_scale_y_finish_;
    float glow_alpha_start_;
    float glow_alpha_finish_;
    float glow_scale_y_start_;
    float glow_scale_y_finish_;

    base::TimeTicks start_time_;
    base::TimeDelta duration_;

    State state_;

    float pull_distance_;

    DISALLOW_COPY_AND_ASSIGN(EdgeEffect);
};

} // namespace ui

#endif // UI_ANDROID_EDGE_EFFECT_H_
